Pharma interview questions and answers – For Formulation production and R&D jobs:

Pharma interview notes:

We have already provided department wise pharma interview question and answers. Also provided qualifying exam papers for interview. Here we covered some more interview Q&A. these notes are also useful for interview. We are dedicated to provide some more interview questions as shown below in the near future. We also provide departmental wise interview notes continuously. Following Q&A are belongs to pharmaceutics which are useful for the production and R&D jobs.

What is corrosion?

It is a metal deterioration process. Due to chemical or chemical reactions or environmental interactions with surface metal, metal surface is gradually destructed. It is an unwanted process. Corrosion leads to machinery damage, product contamination and replacement of damaged machinery increase economic burden to the plant. Corrosion should be avoided by taking preventive measures.

What is passivation?

It is a procedure which makes the stainless steel more rust resistant by reducing the chemical reactivity of surface. Usually citric acid or nitric acid is used to do this process. It removes the free iron from the stainless steel surface. A protective oxide layer will be formed with inert in nature. This layer will less likely react with chemicals or air in the environment. If more layer is formed It will more resistant to corrosion less reactivity with chemicals.

What is the difference between dry bulb and wet bulb temperatures?

These are the temperatures useful to find the state of humid air.

The dry bulb temperature and wet bulb temperature is known as “air temperature” and “adiabatic saturation temperature” respectively.

Dry bulb temperature measured using a thermometer, bulb of the thermometer will be exposed freely in the air. While measuring the wet bulb temperature, bulb will be wrapped in a wet muslin cloth.

Pharma interview notes

What are azeotropes?

Azeotropes are also known as constant boiling mixtures. It is a mixture of liquids that act as a pure liquid having a constant boiling point. The boiling point may be higher or lower than individual component in the mixture’s boiling point. Azeotropes contains same composition of components in both liquid and vapour phase.

For eg:

water boiling temperature : 100 0C,

Ethanol boiling point : 78.3 0C

When a mixture of liquid composed 95% water and 5% ethanol by volume. This azeotrophic mixture will constantly boil at 78.2 0C. By using boiling method or simple distillation, we can not separate water and ethanol from this azeotrophic mixture.

If the mixture contains two liquids, is known as binary azeotropes. If it contains three liquids, it is known as ternary azeotropes.

Mention a few methods to enhance the solubility of poorly soluble drugs?

Various methods are used to enhance the drug solubility are as follows

– Particle size reduction

– Drug salt formation

– Solid dispersion

– Preparing Nano suspension

– Using surfactants

What is lyophilisation?

It is also known as freeze drying technique. In involves following steps

– Freezing: In this step, sterilised partially stoppered containers (drug+ excipients+ solvent) placed in the  freeze drying chamber.

-Primary drying(Sublimation): To sublimate water, pressure is reduced and heat increased. Ice crystals directly converted to vapour bypassing the liquid state. 95% water removed in this phase.

-Secondary drying (Desorption): Remaining bounded water removed in this phase. Temperature is increased more than the primary drying temperature. Then the vacuum is broken and filled with inert gas and sealed.   

This technique is used to preserve the biodegradable materials.

pharma interview notes which are not covered in the previous posts.
What is annealing?

Annealing is also known as slow freezing. When some compounds (ex. Amorphous compounds like mannitol) will not complete crystals. In this case, annealing is used. After forming the crystals, temperature is cycled. (Like -50 C to -30 C for few hours then back to -50 C). This process helps to form larger crystals.

What is osmosis?

It is a phenomenon. When dilute solution and concentrated solution separated by a semipermeable membrane. The  solvent passes from dilute solution to concentrated solution. This pressure is known as osmotic pressure.

Any fluid is injected into the body should be isotonic in nature. If hypertonic fluid injected into the body, it crenation of blood cells. If hypotonic fluid injected into the body, solvent passes in to blood cells causes haemolysis.

Mention a few solubility terms?

Very soluble- 1 part of solute soluble in less than 1 part of solvent

Freely soluble  -1 part of solute soluble in 1-10 parts of solvent

Soluble – 1 part of solute soluble in 10-30 parts of solvent

Sparingly soluble – 1 part of solute soluble in 30-100 parts of solvent

Slightly soluble – 1 part of solute soluble in 100 -1000 parts of solvent

Very slightly soluble – 1 part of solute soluble in 1000-10000 parts of solvent

Practically insoluble – 1 part of solute soluble in more than 10000 parts of solvent

Related: Clinical trials overview

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Interview questions for quality assurance in pharmaceutical industry

Interview questions for quality assurance in pharmaceutical industry:

We have provided interview questions for quality assurance in pharmaceutical industry here. There is no specified differences between quality control and quality assurance from interview point of view. They are all interlinked. But we tried to prepare in separate posts and produced. This post is an extension to our previous interview questions for quality assurance in pharmaceutical industry. If you attending an interview, you have to all these questions and answers in these 4 posts. It helps you a lot to face interview well.

Interview questions for quality assurance in pharmaceutical industry are as follows.

Qa-What do you know about change control?

Changes which were made to materials or procedures or methods or equipment or software should be documented properly. These changes should approved, validated and able to traceable. Change control deals and makes sure all these changes.

Explain about Bracketing and Matrixing study designs in stability testing/

Ans) These are the study designs for stability testing. In a full study design, you have to test the samples of all the design factors at all time points. Bracketing and Matrixing are reduced study designs.

When multiple design factors involved in a study, these are the best alternatives to full study design. If you use these designs, you need not to test all the samples at all time points. These study designs mostly used when multiple design factors involved.

Bracketing: In this schedule, At all time points only extremes of certain study factor (like container fill & or container size or strength etc) samples tested. Bracketing supposes that tested extremes stability represents the intermediate levels stability of that study factor.

Matrixing: In this schedule, at a specific time point a selected subset of the total number of possible samples for all factor combinations would be tested. At a next or subsequent time point, all the factor combinations for another subset would be tested. Matrixing supposes that at a given time point, tested each subset stability represents the all the samples stability.

Before using this study designs, certain assumptions should be evaluated and justified.

NOEL: No Observed Effect Level

MACO: Maximum Allowable Carry Over


Corrective Action and Preventive action. It’s an important part of QMS (Quality Management System). Corrective actions planned to know the cause of the problems which were happened in the past and correct it. Preventive actions intended to prevent the problems that might happen in the future.

Explain about Out of Specification (OOS) results and Out Of Expectation (OOE) results?

Out Of Specification (OOS) results: Analysed test result falling out side the predefined acceptance range or criteria made by company documentation or official compendia.

Out Of Expectation (OOE) results: Although the Analysed test result falls within the specification, this result will falls out side the procedure expected variability.

Interview questions for quality assurance in pharmaceutical industry 

Interview questions for quality assurance in pharmaceutical industry:

Stress Testing:

Also called as Forced degradation study, stress study. Forced degradation study intended to know the degradation products, it will helps us further to know the molecule intrinsic stability, degradation pathways establishment and to validate the molecule stability procedures. Stress testing conducted at the conditions which are more severe than the accelerated study conditions. For a formal stability program, stress testing not considered as a requirement. It is regulatory authority requirement.

What is the purpose/use(s) of stability testing?

Ans) Stability testing gives the confirmation as how the quality of study product changes with time.

It finds out the study product shelf life, recommended storage conditions as well as container closure system suability. Also gives assurance to the patient regarding stability of a drug product. Stability testing is a regulatory requirement also.

What are different types of stability studies along with its conditions?


Long-term stability studies: Storage conditions 25+20C, 60+5% RH and Minimum Time period is 12 months

Intermediate stability studies: Storage conditions 30+20C, 60+5% RH and Minimum Time period is 6 months

Accelerated stability studies: Storage conditions40+20C, 75+5% RH and Minimum Time period is 6 months

Dead leg: Dead logs not allowed in water design systems. These are the stagnant areas with no water flow. It allows microbial contamination resulting the surface colonisation by forming biofilms. If a dead log present in any case, it should have particular pipe diameter and velocity. In general agreement in industry, dead log should not be more than the pipe diameter.

For e.g: If the pipe diameter is 5 cm , then dead log should not be more than 10cm.

Cleaning validation: It is a documented evidence involves the approved cleaning procedure for eliminating the process equipment contaminants. It means the process equipment ready and can be used safely for preparing the next product without any previous contaminants.

These contaminants may be chemical (previous product residues), microbial or Physical (Particulate matter) types. Different types of cleaning agents used in the cleaning validation like aqueous solvents (water, surfactants, acids or bases etc) and organic solvents.

Validation master plan (VMP):

It is a document describes the company’s validation strategy and approach for establishing the performance adequacy. VMP includes all the details and time scales regarding the validation work to be performed.

Process validation:

It provides a documented evidence assuring that a particular process produces a product with predetermined specifications and characteristics consistently.

Four types of process validation available.

Prospective validation: Conducted prior to process implementation to assuring that process is performs as intended on the basis of pre-planned plans.

Concurrent validation: Conducted during the product routine production.

Retrospective validation: Conducted on some products , those products which are already on commercial market. The intention is to establish the long term compliance of that product.

Re-validation: This is nothing but repetition of validation. Conducted to assuring that the changes/modifications done in equipment/process in according to the change control procedures. Those changes are not effecting the equipment/process and their produced products adversely.

This is the second post regarding Interview questions for quality assurance in pharmaceutical industry. You can view the previous post  QA interview questions and answers.

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